1. Field
The present description relates generally to a rechargeable battery and, more particularly, to a rechargeable battery having a cap plate coupled to a case.
2. Description of the Related Art
Unlike a primary battery, a rechargeable battery is a battery configured to repeatedly perform charging and discharging. A rechargeable battery having a small capacity may be used in a portable small electronic device such as a mobile phone, a laptop computer, and a camcorder. A rechargeable battery having a large capacity may be used, for example, as a power source for driving a motor of hybrid and electric vehicles.
A rechargeable battery commonly includes an electrode assembly for performing charging and discharging, a case receiving the electrode assembly and an electrolyte solution, a cap plate fastened to an opening of the case, and an electrode terminal provided in the cap plate and electrically connected to the electrode assembly.
Conventionally, the case is formed by a deep draw process. Additionally, during the deep draw process, a step is formed at a position around the opening of the case. The step is configured to ensure alignment between the cap plate and the case when the cap plate is coupled to the case. Additionally, the cap plate is conventionally mated to the case by a press process.
However, a shape of the step in the opening may be non-uniform due to a technical limit in deep drawing. In that case, the cap plate is difficult to be seated in the opening and the step of the case, and may be over-inserted into the opening.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art.